FR-A-2936784 describes a tank with a corrugated sealing membrane reinforced with reinforcing pieces arranged below the corrugations, between the sealing membrane and the support of this sealing membrane, to reduce stresses in the sealing membrane caused by a multitude of factors such as the thermal shrinkage when the tank is chilled, the effect of flexion of the ship's beam, and dynamic pressure due to movement of the cargo, in particular because of the swell. These hollow reinforcing pieces allow gas to circulate between the corrugations and the support, passing through the reinforcing pieces.
Several solutions have been considered for fixing such reinforcing pieces to the tank wall. It has been proposed to fix the reinforcing pieces to the sealing membrane, for example in FR-A-2936784 (FIG. 12) and WO-A-2012020194. It has been considered to fix the reinforcing pieces to the thermal insulation barrier, for example in FR-A-2936784 (FIG. 11). In all cases, the fixing of the reinforcing pieces must be reliable in order to prevent a reinforcing piece, which has come detached from its support, from causing impacts, in particular against the sealing membrane, which would risk accelerating the fatigue of the materials and increasing leaks.
KR-A-20130119399 teaches a reinforcing element equipped with elastic coupling parts intended to be fixed in holes formed on the upper surface of an insulating panel. However, such elastic coupling parts have the following drawbacks:                These elastic coupling parts do not also allow reliable stoppage of a translation movement in a longitudinal direction of a groove, since they must have a degree of elasticity necessary for their installation.        It is difficult for these elastic coupling parts to ensure an adequate fixing of the reinforcing elements because of the installation tolerances, thermal contractions during chilling of the tank, and elongations of the ship which tend to move the panels apart from each other.        